Peripheral Arterial Disease: The Impact on Quality of Life

Causes and Risk Factors

Peripheral arterial disease (PAD) is a disorder characterized by a chronic reduction in blood flow to the extremities. The disease affects multiple populations. An estimated 4 million people in the United States over 40 have symptoms of intermittent claudication or more severe claudication or ischemia. The prevalence of PAD increases with age. Among those over 65, the prevalence is 15-20%. And among minority groups, prevalence is substantial, estimated at 12.6% of non-Hispanic blacks and 11% of Hispanics. Moreover, PAD is frequently underdiagnosed in individuals with atypical leg symptoms such as burning or aching pain, and in those with typical exertional leg symptoms who do not associate the symptoms as part of an aging process. PAD is frequently associated with other forms of cardiovascular disease, such as coronary heart disease and cerebrovascular disease, with up to 60% of individuals having these conditions. As baby boomers age, there is greater awareness that lower extremity PAD is an important health concern. This increasing public awareness will likely result in more individuals seeking treatment for PAD. An often ignored aspect in the evaluation of many symptomatic diseases is the impact on physical function. The primary care provider needs to understand the net effect of diseases on a patient’s ability to walk and function, as well as to what degree symptoms will potentially limit future functional capabilities. A thorough functional evaluation must be done in an environment that simulates the patient’s everyday function. This usually encompasses treadmill walking tests but may require specific evaluations of muscle strength with handheld dynamometers or isokinetic devices. A complete physiological assessment should be initially done in an inpatient setting with specific measures of gas exchange and determination of claudication threshold using exercise testing with oximetry measurements.

Symptoms and Diagnosis

Symptoms of PAD can be classic or atypical. Classic symptoms include intermittent claudication, which is the presence of pain, aching, cramping, numbness, or a sense of fatigue in the legs due to muscle ischemia. This type of pain occurs reproducibly with a certain level of exercise and is relieved within 10 minutes by rest. It is dependent on the severity of the PAD. Other classic symptoms of PAD are skin changes in the lower limb. The skin will become thin and shiny, the hair growth will be reduced, and the nails will thicken. These skin changes are late manifestations of chronic tissue ischemia. Atypical symptoms can be exhibited in older people and patients with diabetes. They can include atypical leg pain, often in the buttocks, thighs, or calves. The symptoms are atypical due to the patient not necessarily experiencing intermittent claudication. They can also include acute or chronic changes in the function and sensation of the lower limb, which can be due to an acute compaction of a plaque, embolization, or chronic nerve ischemia. Known neurogenic symptoms are termed as leg paresis and paresthesia, which patients often describe as weakness or heaviness of the leg(s) and altered sensations in specific regions of the lower limb. The diagnosis of PAD can be made primarily on the symptoms in the appropriate clinical context. By establishing the presence, character, and laterality of claudication symptoms, it can be determined whether or not the patient has peripheral vascular disease. An atypical cause of ischemic muscle pain can be confirmed if there is evidence of an arterial occlusive disease. This can be determined by comparing the pulsatile signs in the affected limb to those in the unaffected limb. This can indicate a substantial reduction of blood flow in the affected limb. Further evidence of arterial occlusive disease can be obtained by using a hand-held Doppler ultrasound, which can be used to record blood pressure at the toes and the arms to measure the ankle-brachial pressure index. An index of less than 0.9 provides the diagnosis of PAD with a sensitivity of 90% and a specificity of 99%.

Management and Treatment

This is why revascularization therapies are commonly used to alleviate ischemic symptoms. This is particularly beneficial to patients suffering from severe cases of claudication or critical limb ischemia. That being said, the purpose of revascularization to improve quality of life is debated, as it is suggested that revascularization is no more effective than just medical treatment alone, and most studies do not show a significant increase in quality of life. This then suggests that revascularization is more beneficial in terms of prolonging life rather than improving it.

Patients often adopt different management strategies when coping with PAD, one of these strategies being self-care. Self-care necessities, including making lifestyle changes such as quitting smoking and partaking in an exercise plan, have proven to be successful in alleviating symptoms of claudication. Another crucial part of self-care for patients with PAD is foot care. However, the patient must be able to see or reach his feet, which can be impossible for someone with a very severe case of claudication or critical limb ischemia.